The present invention relates to a miter saw, and more particularly, to a miter saw having a compact gear case at a cutting portion.
In a miter saw having a cutting portion provided with a circular saw blade, cutting operation is performed by pivotally moving the cutting portion toward and away from a base portion on which a workpiece is mounted. A power transmission mechanism is provided in the cutting portion for rotating the circular saw blade. The mechanism includes an output shaft fixing the circular saw blade, and gears and pulleys those drivingly connecting the output shaft to a power source such as a motor. Since the power transmission mechanism is disposed nearby a rotation shaft of the circular saw blade, a portion of the cutting portion surrounding the power transmission mechanism may abut against the workpiece during cutting operation, to lower cutting performance.
In a recent miter saw, a bevel cutting at an acute angle between a side surface of the circular saw blade and an upper surface of the base portion is achievable by laterally tiltingly moving the cutting portion. Therefore, the portion of the cutting portion surrounding the power transmission mechanism may abut against the workpiece if the cutting portion is tilted in a lateral direction which is coincident with a projecting direction of the power transmission mechanism from one lateral side of the cutting portion. Therefore, bevel cutting to a thick workpiece my not be easily achievable.
U.S. Pat. No. 6,971,298 discloses a miter saw having a compact power transmission mechanism based on an improvement on the geometrical relationship among shafts, pulleys, and gears those constituting a power transmission mechanism in order to avoid interference between the cutting portion and a workpiece.
However, there is still a problem of interference between the cutting portion and the workpiece in the disclosed miter saw when the cutting portion is laterally tilted in a direction coincident with a projecting direction of the power transmission mechanism from one lateral side of the cutting portion in comparison with a case when the cutting portion is tilted in an opposite lateral direction opposite to the projecting direction of the power transmission mechanism. Further, the bevel cutting when the cutting portion is laterally tilted in the direction coincident with the projecting direction of the power transmission mechanism cannot be performed with respect to a specific standardized member.